As a conventional technique related to RFID, there has been known a technique called semi-active RFID in which electromagnetic waves in two kinds of frequency bands are used, and the power switch of a terminal station having a power source such as a battery is turned on/off to reduce the power consumption of the terminal station used for communications as small as possible using the electromagnetic waves that can be reached far with less electric power (for example, refer to V. Natarajan et al, “Security for energy constrained RFID system” Automatic Identification Advanced Technologies, 2005, Fourth IEEE Workshop on 17-18 Oct. 2005 pp 181-186). In addition, Japanese Patent Application Laid-Open publication No. 2007-199967 discloses a technique using radio waves in the RF band not only when detecting the presence or absence of an object in the same area, but also identifying the position of the object. Further, Japanese Patent Application Laid-Open Publication No. 2007-243821 discloses a technique in which a leakage coaxial cable is used as an antenna of a wireless tag and the leakage coaxial cable is laid in a branching-structure shape.